Method and apparatus for sequential forwarding considering multi-flow in dual connectivity system

A method for transmitting multi-flow data for one evolved packet system (EPS) bearer to user equipment (UE) from a macro base station through the macro base station and a small base station in a wireless communication system supporting dual connectivity, the method comprising:

• generating packet data convergence protocol (PDCP) packet data units (PDUs) in a PDCP entity with respect to packets received by the macro base station according to a PDCP sequence number (SN) of a PDCP service data unit (SDU);
• distributing the PDCP PDUs to radio link control (RLC) entities of the macro base station and RLC entities of the small base station according to a predetermined rule and transmitting the distributed PDCP PDUs to the UE;
• and
• transmitting to the UE a radio resource control (RRC) message including information related to an in-sequence timer for the PDCP SDUs.

A user equipment (UE) for receiving multi-flow data with respect to one evolved packet system (EPS) bearer through a macro base station (macro eNB) and a small base station (small eNB) in a wireless communication system supporting dual connectivity, the UE comprising:

• a receiving unit receiving packet data convergence protocol (PDCP) packet data units (PDUs) through the macro base station and the small base station and receiving from the macro base station information related to an in-sequence timer for the PDCP SDUs through a radio resource control (RRC) message;
• and
• a processor obtaining PDCP service data units (SDUs) corresponding to the PDCP PDUs,
• wherein the PDCP SDUs are indicated by a predefined PDCP sequence number (SN).